Cryptoblepharus egeriae (Boulenger, 1889:535)

Blue-tailed skink, Christmas Island forest skink, Christmas Island blue-tailed shinning-skink



Taxonomy & Nomenclature

Synonym/s: Ablepharus egeriæ Boulenger, 1889:535 (basionym); Ablepharus egeriae Boulenger, 1889:535


Conservation Status

Extinct in the wild

IUCN RedList status: Extinct in the Wild


Smith et al. (2012) reported that a single population of Cryptoblepharus egeriae persisted in the southwestern end of the island, however this population seems to now be extinct (Woinarski & Cogger, 2013).


"The species was considered to be abundant in the late 1970s. Declines were first reported in 1992 (Rumpff, 1992) and it has subsequently undergone a dramatic decline in numbers.  From August 2009 as many individuals as possible were taken into captivity, a total of 64 animals, in order to develop a captive breeding programme (Andrew et al., 2016). It was last recorded in August 2010 (Andrew et al., 2016) and many recent intensive surveys in the island, at appropriate times, seasons, and habitats have not recorded the species again. There is a successful captive breeding programme and the population is increasing (Andrew et al., 2016)."

(Woinarski et al., 2017)



Christmas Island, Australia


Biology & Ecology

"Ecology: closed forest, peridomestic, terrestrial, arboreal, diurnal; arthropod-feeder, oviparous."

(Cogger et al., 1983:141)




BMNH 1946.8.15.86 (Cogger et al., 1983:141)

BMNH 1946.8.15.87 (Cogger et al., 1983:141)

BMNH 1946.8.15.88 (Cogger et al., 1983:141)

Type locality: "Christmas Isl., Indian Ocean" (Cogger et al., 1983:141)






Original scientific description:

Boulenger, G. A. (1889). On the reptiles of Christmas Island. Proc. Zool. Soc. London 1888: 534-536.


Other references:

Agius, Jessica Esther et al. (2021). Genomic Insights Into the Pathogenicity of a Novel Biofilm-Forming Enterococcus sp. Bacteria (Enterococcus lacertideformus) Identified in Reptiles. Frontiers in Microbiology 12: 635208.

Andrew, Paul, Cogger, Hal, Driscoll, Don, Flakus, Samantha, Harlow, Peter, Maple, Dion, Misso, Mike, Pink, Caitlin, Retallick, Kent, Rose, Karrie, Tiernan, Brendan, West, Judy and Woinarski, John C. Z. (2016). Somewhat saved: a captive breeding programme for two endemic Christmas Island lizard species, now extinct in the wild. Oryx 52(1): 171-174.

Boulenger, G. A. (1900). Reptilia, pp. 51-54. In: Andrews, C. W. (ed.). A Monograph of Christmas Island (Indian Ocean). British Museum of Natural History, London, UK.

Chapple, D., Tingley, R., Mitchell, N., Macdonald, S., Keogh, J. S., Cox, N., Bowles, P., Shea, G., & Woinarski, J. (2019). The action plan for Australian lizards and snakes 2017. CSIRO Publishing.

Cogger, Harold G., Cameron, Elizabeth E. and Cogger, Heather M. (1983). Scincidae, pp. 135-193. In: Zoological Catalogue of Australia. I. Amphibia and Reptilia. Canberra: Australian Government Publishing Service. vi + 313 pp. [p. 141]

Cogger, H. G. and Sadlier, R. A. (1981). The terrestrial reptiles of Christmas Island, Indian Ocean. Australian Museum, Sydney. 194 pp. Report to the Australian National Parks & Wildlife Service. [relevant citation?]

Cogger, H., Sadlier, R. A. and Cameron, E. (1983). The Terrestrial Reptiles of Australia's Island Territories. Australian National Parks and Wildlife Service, Special Publication No. 11. Australian Government Publishing Service: Canberra. 80 pp.

Dalrymple, S. E., Abeli, T., Ewen, J. G., Gilbert, T. C., Hogg, C. J., Lloyd, N. A., Moehrenschlager, A., Rodríguez, J. P. and Smith, D. (2023). Addressing Threats and Ecosystem Intactness to Enable Action for Extinct in the Wild Species. Diversity 15: 268.

Tristram Dodge, Katherine Farquharson, Claire Ford, et al. Genomes of two Extinct-in-the-Wild reptiles from Christmas Island reveal distinct evolutionary histories and conservation insights. Authorea. November 29, 2022. DOI: 10.22541/au.166974487.73559017/v1

Emery, Jon-Paul. (2021). Planning the recovery of two Extinct in the Wild lizards on Christmas Island. PhD thesis, The University of Western Australia.

Emery, Jon-Paul et al. (2021a). Survival of an Extinct in the Wild skink from Christmas Island is reduced by an invasive centipede: implications for future reintroductions. Biological Invasions 23: 581-592.

Emery, Jon-Paul et al. (2021b). The lost lizards of Christmas Island: A retrospective assessment of factors driving the collapse of a native reptile community. Conservation Science and Practice 3:e358.

Geyle, Hayley M. et al. (2021). Reptiles on the brink: identifying the Australian terrestrial snake and lizard species most at risk of extinction. Pacific Conservation Biology 27: 3-12.

Lister, J. J. (1888). On the natural history of Christmas Island in the Indian Ocean. Proceedings of the Zoological Society of London, 512-531. [relevant citation?]

Low, Tim and Booth, Carol. (2023). GONE: Australian animals extinct since the 1960s. Invasive Species Council Inc.

Mertens, R. (1931). Ablepharus boutonii (Desjardin) und seine geographische Variation. Zool. Jahrb. Syst. 61: 63-210.

Oliver, Paul M., Blom, M. P. K., Cogger, Hal G., Fisher, R. N., Richmond, J. Q. and Woinarski, J. C. Z. (2018). Insular biogeographic origins and high phylogenetic distinctiveness for a recently depleted lizard fauna from Christmas Island, Australia. Biol. Lett. 14: 20170696.

Rumpff, H. (1992). Distribution, population structure and ecological behaviour of the introduced South-East Asian wolf snake Lycodon aulicus capucinus on Christmas Island, Indian Ocean.

Smith, Donal et al. (2023). Extinct in the wild: The precarious state of Earth’s most threatened group of species. Science 379(6634): eadd2889.

Smith, Michael J., Boland, Christopher R. J., Maple, Dion and Tiernan, Brendan. (2012). The Christmas Island blue-tailed skink (Cryptoblepharus egeriae): a survey protocol and an assessment of factors that relate to occupancy and detection. Records of the Western Australian Museum 27(1): 40-44.

Woinarski, John C. Z., Braby, M. F., Burbidge, A. A., Coates, D., Garnett, S. T., Fensham, R. J., Legge, S. M., McKenzie, N. L., Silcock, J L. and Murphy, B. P. (2019). Reading the black book: The number, timing, distribution and causes of listed extinctions in Australia. Biological Conservation 239: 108261.

Woinarski, John and Cogger, Hal. (2013). Australian endangered species: Christmas Island Forest Skink. The Conversation, 19 September, available online:

Woinarski, J., Cogger, H., Mitchell, N. M and Emery, J. (2017). Cryptoblepharus egeriae. The IUCN Red List of Threatened Species 2017: e.T102327291A102327566. Accessed on 10 June 2022.


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